The present invention relates to a semiconductor device and its manufacturing method, particularly relates to technique which is effectively applied to a ball grid array (BGA)-type semiconductor device wherein a package including a semiconductor chip is mounted on a printed wiring board via a solder bump.
A ball grid array (BGA) wherein a solder bump is mounted on one surface of a package including a semiconductor chip and the package is mounted on a printed wiring board via the solder bump has an advantage that multiple pins can be more easily provided, compared with a quad flat package (QFP) from the sides of which leads are pulled out and a small outline package (SOP) and packaging area can be reduced.
For the BGA, various structures are proposed, however, particularly, for BGA suitable for packaging to small lightweight electronic equipment such as portable information equipment, a digital camera and a notebook-sized personal computer, a tape carrier package (TCP) in which a package is configured by an insulating tape is well-known. This type of tape BGA (TBGA) is disclosed in Japanese published unexamined patent applications No. Hei 7(1995)-321248, No. Hei 8(1996)-88243 and No. Hei 8(1996)-111433 for example.
Also, these inventors develop BGA provided with the following structure (particularly fine pitch BGA in which pitch between bumps is narrowed). For the BGA, a device hole is formed in the center of a wiring board made of resin on one side of which plural leads made of Cu (copper) foil are formed, a semiconductor chip is arranged there, the semiconductor chip and one end of the lead are electrically connected via a bump electrode made of Au and the main surface of the semiconductor chip is sealed with potting resin. Also, the other end of the lead is extended to the periphery of the wiring board to be a land, and a solder bump to be a terminal for connecting to an external device of BGA is connected to the land.
Further, for reinforcing materials for enabling securely positioning the solder bump in the land in a process for assembling the BGA, a square metallic frame is applied on the surface on the reverse side of the surface to which solder bumps are bonded in the periphery of the wiring board by an adhesive, and prevents the periphery of the wiring board from being warped.
However, as the metallic frame used for the BGA is formed by stamping a thin metallic plate made of Cu (copper) or the like using a press, applying an adhesive to one side and further applying a cover tape for protecting the adhesive to the surface, the material is high-priced and it increases the manufacturing cost of the BGA. Also, as work for applying the metallic frame to the wiring board is required, the number of manufacturing processes for the BGA is increased. In this work for applying the metallic frame, removing the thin cover tape for protecting the adhesive cannot be well performed by a robot hand, it is also difficult to reduce the cost by automation.
The object of the invention is to provide technique that can reduce the manufacturing cost of BGA including tape BGA and fine pitch BGA.
Another object of the invention is to provide technique that can enhance the reliability of BGA including tape BGA and fine pitch BGA.
The object, another object and new characteristics of the invention will be clear from the description of the specification and attached drawings.
The summary of the representative of the inventions disclosed in the present invention will be briefly described below.
A semiconductor device according to the invention is provided with a semiconductor chip, a wiring board provided so that the wiring board surrounds the semiconductor chip, plural leads which are formed on the wiring board and one end of which is electrically connected to the semiconductor chip, sealing resin for coating the semiconductor chip, a reinforcing frame provided along the periphery of the wiring board, and plural bumps arranged along the periphery of the wiring board and electrically connected to the other end of the lead, and the reinforcing frame is made of resin.
Also, a semiconductor device according to the invention is provided with a semiconductor chip, a wiring board provided so that the wiring board surrounds the semiconductor chip, plural leads which are formed on the wiring board and one end of which is electrically connected to the semiconductor chip, sealing resin for coating the semiconductor chip, a reinforcing frame provided along the periphery of one main surface of the wiring board, and plural bumps arranged along the periphery of the other main surface of the wiring board and electrically connected to the other end of the lead, the reinforcing frame is made of resin, a through hole that pierces the upper and lower surfaces of the reinforcing frame and the wiring board and reaches the lead is provided to the reinforcing frame and the wiring board, and conductive material is embedded inside the through hole.
Also, the manufacturing method of the semiconductor device according to the invention includes the following steps:
(a) a step for arranging the semiconductor chip in the device hole of tape base material having plural leads one end of which is extended inside the device hole and in a part of the other end of which a land for connecting a bump is formed, and electrically connecting the semiconductor chip and one end of the lead;
(b) a step for forming the sealing resin for sealing the semiconductor chip and the reinforcing frame that surrounds the sealing resin by transfer molding;
(c) a step for connecting a bump to the land of the lead; and
(d) a step for removing an unnecessary part of the tape base material.
As a method for providing a high-priced metallic frame to the wiring board is not required according to the invention described above, the cost of the material and the number of manufacturing processes can be reduced and BGA of a low cost can be provided. Also, BGA whose reliability is enhanced can be provided by sealing the semiconductor chip with resin by transfer molding.